Oxyphosphoranes synthesis

A particular application of this type of synthesis involving aldehyde addition to the intermediate oxyphosphorane is in the preparation of... 

The year s reviews cover phosphorylated indoles, phosphorus-selenium compounds, phosphoryl carbenes, phosphorus-sulphur compounds, and steroid phosphates, as well as the synthesis of phosphorus esters via oxyphosphoranes. A review on phosphonates contains many interesting applications of some of the well-tried syntheses of these as analogues of natural phosphates. ... 

An improved synthesis of 5-acetyl-2-methoxy-5-methyI-2,4-dioxo-l,3,2-dioxa-phospholan (8), starting from the oxyphosphorane (7), has been reported, as has one of the enediol cyclic phosphoryl chloride (9 R==C1) from (9 R=OMe) via the corresponding pyrophosphate by reaction with phosgene-pyridine (see Organophosphorus Chemistry , Vol. 8, p. 106). ... 

Oxyphosphorane chemistry has been reviewed, with emphasis being placed on the importance of ligand sub-set symmetry in determining the relative stabilities of isomeric trigonal-bipyramidal phosphoranes, the effect being more pronounced for the equatorial than for the apical system. Applications of oxyphosphoranes in synthesis have also been reviewed. ... 

The routes and have both been considered for the reaction between propenal (R = H) and trimethyl phosphite, and hydrolysis of the oxyphosphorane yielded 3-(dimethoxyphosphinoyl)propanal. The phosphorane, 580 (R = Et), obtained from triethyl phosphite and but-3-en-2-one has been mentioned earlier in connection with the synthesis of phosphonic diesters possessing both oxo and hydroxy groups" as an example of its further usefulness through treatment with an electrophile, its reaction with bromine yields the bromo ester 581 and this, when heated, undergoes dehydrobromination to give diethyl (3-oxobutenyl)phosphonate (582), also obtained when 580 is heated with nbs. ... 

Examples of the synthesis of phosphite and phosphate esters of sugars are included in a review on trivalent phosphorous acids (Scheme 5). The synthesis of an oxyphosphorane has also been reported (Scheme 6). A strategy for regioselective phosphorylation of aldoses in aqueous solution involves reversible attachment of activated diamidophosphate (DAP). The carbonyl addition prod-... 

GMP has been prepared from guanosine by an enzymic method, and an improved synthesis of guanosine 5 -monothiophosphate from 2, 3 -0-iso-propylideneguanosine, which avoids the need for chromatography, has been described. The pyrimidinone 7 has been converted into the 5 -phosphate 190, for use in studies of covalently-linked base pairs. Nucleotide libraries of type 191 (X = O, S) have been assembled using solid-phase techniques. The uridine-derived 5 -oxyphosphorane 191a has been prepared from the 5 -phos-phite and o-chloranil. ... 

The four-membered oxyphosphorane ring system is involved as an (usually unstable) intermediate when a phosphorane reacts with a carbonyl compound in the Wittig synthesis (6.415). Some of these intermediates have, however, been isolated and their ring structures confirmed by x-ray analysis (Figure 6.27). From the reaction of hexafluor acetone with hexaphenylcarbodiphosphorane in the presence of 1,2 diethoxyethane (diglyme), colourless crystalline 4,4 bis (trifiuoromethyl)-2,2,2 triphenyl-3-(triphenylphosphoranylidene)-l,2 oxa phosphetane, mp=115 C, can be obtained. 

---